Tuberculosis diagnostic composition



Patented May 22, 1951 TUBERQULOSISIDIAGNQSTIC COMPOSITION Harry J. Grper, Denver, "0010., ass'ignor -to The National Jewish flospitaL' Denver,*Colm, a cor- :poratiomofflmorado iNoillrawing. A nIicationNQvemherB,1346, "Serial No.'71)..8,791

J31Glaims. 1

The-invention relates toad-hesivesand to transparent dried films thereof. More "particularly, the invention relates "to 'a skin adhesive and to transparent "dried .films thereof containing an agent which can "act transdermally on human :Skin "for the production 'of medical, therapeutic, "diagnostic "and biological efiects. The inven- 'tion also relates to :such adhesives which are capable.;o'f"being'spread, sprayed "or painted onto "ithe surface .of the "skin :and which quickly dry "to form flexible, 'but adherent, transparent films which ,do not "hermetically seal the active agent within .th'ebody of theifilm, but which gradually irelease it under the influence of *the normal imoisture andlinsensible perspiration ofthe skin, while at the same time allowing the skin to breathe 'sufficiently .to prevent skin macera- ;tion and reddening, with consequent masking *of' the true results based "upon the active agent itself.

Infthe past, various means have been'employed to bring medicaments "and the -like "into "contact with 'the skin. For example, various vehicles such as salves, pastes, .ointments, varnishes, -ad- "hes'ive "ltape's :and the like {have been used -in 'orderto apply antiseptics and germicides to -the skin "for ithe p pose of keeping the surface of the-skin sterile .and free "from microorganisms. "However, employment of the .prior combinations has inggeneral beengaccompanied,bymanydrawbacks. 'Th'eknown preparations have only "exrerclsed :a superficial action and the. active agent hasnot penetrated through the skin'to'an extent permitting it to exercise a deeper and --more reliable action onthehuman'body.

Among the objections .to the prion-prepara- '"tions :are the 'use "therein of antiseptic orlike egents active at the surface of the skin but not transdermally active, useof a vehicle 'whichiimprisons the active :agent Within ,it "and only ;per-

, mits utilization of 'the relatively yery small amount present at the point where the film or match directly contacts the skin, ":use of a-vehicle ,does not .leave :a transparent 'film on the "skin *that will permit the condition of the latter to be observed at all times,use of a combination which does not allow the 'insensible leterious and undesirable action -separate from iflthait =01 *the active agent incorporated into the ve'liicleguse' of a=-com'bination which deesnot 'dry 2 -quickly or which =is easily removed, either mechanically or by action of watennse of:a combination which when dried upon the skin is brittle or without the necessary flexibility, iuse of a vehicle-which reacts with or destroysthe acfive agent, use of a vehicle whichneither keeps the active'agent' in suspens'ionnorallows of teady resuspension of active agent whichhas settled *out or packed down hard in the bottom-of a-container for the same, and use i of *-a solvent for the V combination which contains-water or whichiis not perfectly dry or which takes =up "moisture too rapidly from the atmosphere upon standing.

'The'above mentioned objections to prior products indicate 'the exacting requirements fora satisfactory skin adhesive useful for its medical, therapeutic, diagnostic and biological e'iiects,

especially whenthe active agent being used is a transdermally active substance which must not only contact'th'e surface of the skin but must also *be continuously kept in contact therewith and caused to penetrate therethrough in substantial amounts.

-I have 'found'that theiobjections-above referred to are overcome and that commercially 'use'ful,

tare those wherein the active ,-,agent :is effective ntransdermallywn human or animal skin, :where in also itheqcelluloseetheris a water insoluble iloiwer :alkyl ether :of cellulose -.-which -is pervious to Water :and {wherein the suspending liquid has .a specific. gravityeapproximatelyzthe same-as the activaagent.

The :iollowing a examples will serve to illustrate the .invention.

Example 1 "'5 grams of eth-yl cellulose, I having .:a medium ethoxy "content to 4615 and -a viscosity of approximately lll'o centipoises per second initoluene-ethanol solvent (.60.:Ai0), are stirred and dissolved in enough of a mixture of 8 volumes of dry carbon tetrachloride and zvolumes of drygchloro- I form to 'give "cc. of -adhesive solution. 20

grams of dry, powdered :and highly hygroscopic autolytic tuberculin, :prepared for example as *described in my copendin g application,.Serial' No.

643F4 1, filed January 26, 1946, are :then stirred uniformly into the solution oT ethyl c ellulose' in carbon tetrachloride-chloroform. A uniform suspension is thus obtained. It is non-inflammable and the suspending adhesive liquid has just the right specific gravity (approximately 1.57 to keep the tuberculin uniformly suspended so that it does not separate out either at the surface of the liquid or at the bottom of the container. Moreover, the solvent in this preparation is sufficiently volatile to evaporate fairly rapidly (in a few minutes) in contact with the skin of the living body to give an adherent uniform, clear, transparent, flexible dry film without boiling or forming bubbles inthe film or producing opacity thereof due to too rapid evaporation. The final liquid preparation of this example also has the correct viscosity to make it easy to collect an appreciable amount on a glass rod or tooth pick or like simple applicator and apply in one or two strokes as a uniform thin film or patch on the skin. It is more viscous than water but will readily pour from a container and is a thinner liquid than molasses.

' The dry films of this example, which form when the liquid is spread over the skin, are adherent, yet flexible, and clearly transparent so that the color and condition of the skin underneath can be readily observed at all times. Furthermore, the dry films of this example, although water insoluble, are nevertheless pervious to water to the extent that perspiration does notv accumulate under them and cause a macerated and reddened condition of the skin which would interfere with reliable testing or diagnosis. This feature of perviousness to water and moisture is important because it permits the highly hygroscopic autolytic tuberculin incorporated into the film to' take up moisture from the skin and feed its way down through the body of the film into direct contact with the skin.

The tuberculin present in the dry films of this example is especially valuable when testing for tuberculous subjects because it is transdermally highly active and can be used in excess without danger because it is only taken up by the skin to the extent necessary to elicit a skin reaction or reddened and perhaps edematous condition of the skin. It has the advantage of keeping indefinitely in a water-free solvent and it does not produce untoward focal or general reactions, nor does permanent scarring occur at the local site of reaction.

' Example 2 25 grams of standard ethyl cellulose having an ethoxy content of 48.5 to 49.5% and a viscosity in 5% solution of toluene-ethanol solvent (80:20) of 200 centipoises, are-dissolved in enough of a mixture of 5 volumes of tetrachloroethylene and 5 volumes of chloroform to give 500 cc. of adhesive solution. 100 grams of dry powdered and highly hygroscopic autolytic tuberculin, prepared for example as described in my copending application, Serial No. 643,744, filed January 26, 1946, are stirred into the solution. The uniform suspension thus obtained has properties similar to that of Example 1 and is a commercially and clinically valuable preparation.

Example 3 time. 100 grams of dry autolytic tuberculin powder prepared for example as described in my copending application, serial No. 643,744, filed January 26, 1946, are added to the chloroform solution while stirring thoroughly. The glass flask containin the resulting suspension is stoppered by a tin-foil coated cork. The adhesive suspension thus obtained is uniform when first made up and is satisfactory for immediate use as a diagnostic testing material to be applied to the skin of subjects to determine if they are tuberculous. However, since chloroform alone is used as a solvent for the ethyl cellulose, it does not have the necessary specific gravity to insure that the suspended tuberculin will not settle out upon storage. Hence, it is desirable to convert the suspension into a more practical form which is permanent and retains its uniformity. For this purpose, I have found that any of my new suspensions, including the chloroform suspension of the present example, may be spread out in the form of thin films on a suitable fiat surface, such as a glass plate, and dried while taking care not to cause too rapid removal of solvent and formation of bubbles in the film. I prefer to dry the films under controlled partial vacuum at ordinary room temperature. Before the films are completely dried and while they retain a certain degree of flexibility, they can be cut into any desired shapes and sizes. For example, strips 0.3 by 1.0 centimeter can be cut out on the plate and the individual strips separated from the plate by a thin sharp blade which peels them away from the glass without substantially altering their shape. After the strips are thus separated, the vacuum drying is continued until all of ,the chloroform is removed. These individual skin of the forearm or other site .of an individual and which film has a transparency permitting one to readily observe the presence or absenceof a positive skin reaction. If a positive reaction occurs, it will appear within 24 or 48 hours, or in some cases earlier, and maypersist for a period of 10 days to 2 weeks in many instances. If it is desired to remove the test material at any time it can be done by applying a few drops of chloroform, acetone-alcohol mixture or any other suitable solvent for the ethyl cellulose.

From the above example, it will be apparent that the invention includes dry films as well as the liquid adhesive forms from which the dry films are prepared. Either formis valuable as an article of trade. However, both forms are hygroscopic and the usual precautions against absorption of water during preparation and use should be observed.

Example 4 10 grams of ethyl cellulose, standard ethoxy type having an ethoxy content of 48.5 to 49.5% and a viscosity in 5% solution of toluene-ethanol (:20) of '7 centipoises, are dissolved in enough of a mixture of 4 volumes of carbon tetrachloride and 1 volume of chloroform to give 100 cc. of adhesive solution. 20 grams of dry powdered and highly hygroscopic autolytic tuberculin, prepared as described in my copending application, Serial No. 643,744, are stirred uniformly into the solution. The uniform suspension thus obtained is similar to that of Example 1 and can be used in the same manner. However, it is of somewhat lower viscosity, but still has satisfactory covering power.

In the examples given above the active agent is a tuberculo protein made as described in my copending application, Serial No. 643,744. It is highly hygroscopic and readily takes up 90% or more of its weight of moisture from the air upon exposure thereto. Wherever in the appended claims I refer to a ,hygroscopic transdermally active undenatured tuberculo protein I wish to be understood as referring to such hygroscopic protein whether made by the exact method described in my application, Serial No. 643,744, or by methods giving an equivalent protein product.

Instead of using a tuberculo protein in my preparations, other transdermally biologically active substances and hygroscopic protein preparations may also be used, such for example as many of the Well known allergens, particularly those obtained by hydrolytic or autolytic methods from more complex natural substances, which at the same time have the necessary hygroscopicity.

A lower alkyl ether of cellulose, or mixtures of such others, which are insoluble in Water but which nevertheless form dry films permeable to water can be used in the invention. For example; suitable ethyl celluloses which I can use are those wherein the cellulose has been ethylated to the extent of an average of about 2.4 to 2.5 ethoxy groups (-OC2H5) per glucose residue of cellulose. Specifically, the ethyl celluloses which can be used are those having an ethoxy (-OCzHs) content between about 44% and 50%.

In general, when making the liquid adhesive suspensions of my invention, I use solutions in the organic water immiscible solvents of from 1 to of cellulose ether and preferably about 5%.

Moreover, when making up the liquid adhesive suspensions I incorporate anywhere from 10 to 30% of active agent such as tuberculo protein. Thus, when the liquid preparations are thoroughly dried they contain anywhere from about 50% up to about 95% of active solid hygroscopic substance. In the case of autolytic tuberculin 6 prepared by my Serial No. 643,744, I prefer to use about 20% concentration of the same suspended in the liquid adhesive preparation, although percentages anywhere, from about 10 to 30% will give good results.

From the above description it is apparent that the dry films of the invention can be made from any of the liquid preparations described merely,

by careful drying or evaporation.

What I claim is:

1. A liquid, essentially non-aqueous, diagnostic testing material comprisin a suspension of from 10 to 30% by weight of transdermally active autolytic tuberculin in a solution of from 1 to 10% by weight of a water-insoluble but water-permeable ethyl ether of cellulose in a voltatile waterimmiscible inert organic solvent having approximately the same specific gravity as said autolytic tuberculin, said liquid being capable of quickly drying into a skin-adherent film.

2. A liquid, essentially non-aqueous, diagnostic testing material comprising a suspension of from 10 to 30% by weight of transdermally active autolytic tuberculin in a solution of from 1 to 10% by Weight of a Water-insoluble but water-permeable ethyl ether of cellulose in a volatile waterimmiscible inert organic solvent consisting of carbon tetrachloride and chloroform, said liquid being capable of quickly drying into a skin-adherent film.

3. A liquid, essentially non-aqueous, diagnostic testing material comprising a suspension of about 20% by weight of transdermally active autolytic tuberculin in a solution of about 5% by weight of a water-insoluble but water-permeable ethyl ether of cellulose with an ethoxyl content between about 44 and 50% in a volatile water-immiscible inert organic solvent consisting of approximately 4 parts of carbon tetrachloride and. one part of chloroform, said liquid being capable of quickly drying into a skin-adherent film.

HARRY J. CORPER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,278,339 Vollmer Mar. 31, 1942 2,422,866 Vollmer June 24, 1947 OTHER REFERENCES Ecker in Surgery, October1942, pages 631-634, reprint in 167-63 S. 

1. A LIQUID ESSENTIALLY NON-AQUEOUS DIAGNOSTIC TESTING MATERIAL COMPRISING A SUSPENSION OF FROM 10 TO 30% BY WEIGHT OF TRANSDERMALLY ACTIVE AUTOLYTIC TUBERCULIN IN A SOLUTION OF FROM 1 TO 10% BY WEIGHT OF A WATER-INSOLUBLE BUT WATER-PERMEABLE ETHYL ETHER OF CELLULOSE IN A VOLTATILE WATERIMMISCIBLE INERT ORGANIC SOLVENT HAVING APPROXIMATELY THE SAME SPECIFIC GRAVITY AS SAID AUTOLYTIC TUBERCULIN, SAID LIQUID BEING CAPABLE OF QUICKLY DRYING INTO A SKIN-ADHERENT FILM. 